When used over a remote-network uttermost care should be taken in the securityof this (such as TLS/SSL encrypting the connection) and even then storing anyvalid password for such 'virtual' users is probably a bad idea in itself.

Kerberos provides for a far superior single-sign-on authentication system(the 'shadow' part in these setups) in both performance and security.

Besides, this may break stuff so bad you'd need console access to fix it...For some basic installation instructions though see README.SLACKWARE